Rob Marciano has been named co-anchor of CBS Television Distribution’s celebrity newsmagazine Entertainment Tonight. He will co-anchor with Nancy O’Dell beginning in January 2013. Marciano succeeds Mark Steines, who left in July after 17 years. Marciano comes to ET from CNN, where he has been a news and weather anchor since 2003. He also has served as a field correspondent and fill-in anchor at the cable news network.